In today's communications, digital networks transport large amounts of information. Network services can be, for example, traditional voice phone, facsimile, television, audio and video broadcast, and data transfer.
Communication controllers are required to handle frames that are compliant with various communication protocols. Each protocol of the protocol suite is usually detectable by dedicated fields that are usually part of the frame header. The following headers illustrated some commonly used headers: (i) UDP or TCP or SCTP header followed by an IP header and an Ethernet header, (ii) UDP or TCP or SCTP header followed by an IP header, PPP header, PPPoE header and an Ethernet header, (iii) AAL2 header followed by an ATM header, (iv) UDP or TCP or SCTP header followed by an IP header, Ethernet header, RFC2684b header, AAL5 header and ATM header, (v) UDP or TCP or SCTP header followed by an IP header, RFC2684r header, AAL5 header and ATM header, (vi) UDP or TCP or SCTP header followed by an IP header, PPP header, PPPoE header, Ethernet header, RFC2684b header, AAL5 header and ATM header, (vii) UDP or TCP or SCTP header followed by an IP header, PPP header, RFC2684-LLC header, AAL5 header and ATM header.
Interworking includes receiving a frame of a first type and converting it to a frame of another type. Typical interworking includes converting Ethernet frames to AAL5 frames or AAL2 frames, and the like. Interworking is usually used in order to bridge between network that use different protocol suits.
A typical frame processing sequence starts by receiving the frame, parsing its header to determine the type of the frame (which communication protocol), and performing various processing stages in response to the type of the frame.
The following patents and patent applications illustrate various methods and devices for parsing frames: U.S. Pat. No. 6,954,789 and U.S. patent application publication serial number 2004/0083299 of Deitz et al., U.S. patent application publication serial number 2004/0078480 of Boucher et al, and U.S. Pat. No. 6,356,951 of Gentry.
There is a need to provide an efficient method and device for processing frames.